The twist disc is a device which helps train the user's waist and legs. Easy to use, it is quite popular.
The conventional twist disc structure is as shown in FIG. 1, comprising a base disc 1 and a movable disc 2. A vertical axle 11 is fixed in the center of the base disc 1 for pivotally inserted thereon the movable disc 2. Multiple support elements 3 are disposed between the base disc 1 and the movable disc 2 so that the base disc 1 and the movable disc 2 may perform relative motion. The upper surface of the movable disc is provided with a non-skid surface upon which the user stands. To use the twist disc in exercise, the user simply stands on the twist disc and twists his/her trunk, and the twist force is transmitted via the legs so that the movable disc 2 turns on the base disc 1, achieving the object of exercising the muscles of the waist and the legs.
However, the conventional twist disc does not have any other functions other than the one mentioned above. Therefore, it may be helpful to those who want to lose weight, but to most people, it is not very useful.